Method of making rubber products



April 10, 1945.

C. L. BEAL METHOD OF MAKING RUBBER PRODUCTS Filed May '29, 1942 2 cohol or acetone, and preferably, but not necessarily, containing in addition a rubber coagulent to facilitate subsequent deposition of rubber from the liquid dispersion, as when latex is-utilized. The pulverulent material may be dusted in dry form on the entire exposed surface of" the rubber layer, or may be otherwise applied. Other sens-- rating materials such as cellulose ester or cellulose ether or cellulose ether films deposited from solution may be used. It is also possible to treat the entireexposed surface of, the initial rubber deposit with a chemical such as a solution of bromine, chlorine, sulfur chloride, and the like, to

destroy the cohesive character of the rubber.

After application of the separating layer or other adhesion-preventing treatment, the form. together with the associated coatings, is immersed in a liquiddispersion of rubber II to the top edge of the separating material (Fig. 5) thereby producing a second layer of rubber I! over the unand'will have to be derlying deposit and separating coating. resulting ly nested relation. This second deposit of rubber is usually made of 'a thickness equal to that of the first deposit. I The two deposits-are washed and thoroughly dried preferably while still on the form.- The nested bags are stripped from the form and the bags are sealed-such as by pressing the edges together-and vulcanizing.

- in two entirely separate and distinct superposed rubber bags of the shape shown, disposed in closex To complete the assembled rubber safety device,

- an opening is made in both bagsnear one end of the bags and a screw type valve is inserted in the opening. The valve has a spring clamp is on one end. A metal cartridge III \of compressed gas,

such as carbon dioxide, is passed through the opening in the bags and placed so asto be held by the metal clamp. The valve is then sealed by screwing it down tightly, thereby completing the assembly of the swimmers safety device. (Figs. 6

and 7). This emergency device can be adapted into a belt intended to fit around a swimmers mid-section or it can be placed in-a fabric bag as partof a harness assembly to be worn by boatmen, hunters, fishermen, or anyone who is in danger of falling in the water. In an emergency, one end 2| of the metal cartridge 29. said end being lightly constructed, can be broken, thus releasing the gas, inflating the rubber bags, and thereby producing added buoyancy for the immersed one. The construction of the safety device is shown (Fig. 6) with the spring clip IQ of the valve [9 engaging the carbon dioxide cartridge 20 and with a portion of the rubber walls cut away to show the separate and superposed rubber bags I: and H in closely nested relation.

A cross-section of the article is'shown (Fig. 7) taken along the line l'! of Fig. '6. This also shows the valve It with thegas-filled cartridge III in place, as well as the closely-fitted construction of the two expansible bags.

By making the article in the above manner with'the grooves or channels folded inwardly, a safety device is made that is compact in size when deflated and with the channels allowing for expansion to a relatively large size. Because the two rubber bags are in superposed, closely nested, relationship they allow the compressed gas to expand without putting any undue stress on the walls. There is more strength present than if a single-walled article were made with the single wall equal in thickness to the sum of the thickness of the two single-walled bags. The "internested close fitting of the two bags distributes the inflation stresses between the two bags more uni formly than in prior devices materially to safety.

In an alternative procedure designed to eliminate the careful manipulation required to dip the form to precisely the same depth in the successive baths, a small portion at the top of the initial fiowable dispersions of rubber and analogous natural or synthetic gums and resins in liquid vehicles,. whether solvents or non-solvents for rubber. such liquid dispersions may contain any stabilizing, vulcanizing, age-resisting, or other compounding agents, and may be thickened, concentrated, or otherwise conditioned for use according to any of the well-known practices.

I have described herein; preferred method of making the article which is the subject of this invention but the article may be made in any desired way, such as by using separate forms of similar shape with one .of the forms slightly smaller than the other and then the article by placing the slightly smaller bag inside the larger.

This application is a division of my oopending- 85 application, serial No. 311,802, filed December 80,

40 ferred method for making it, it is my desire that the invention beprotected. broadly, limited only 1939, which has since issued as U. 8. Patent No.

2,291,068, grant'edJuly 28, 1942.

Having described the construction and use of the swimmer's safety device together with a preby the spirit and scope of the appendedclaims. I claim:

' i. The method of making a baseshaped rubber article of the character described which comprises providing a form having a channel in the surface thereof, coating the channeled form with rubber having a cohesive exposed surface, treatingthe entire exposed surface of the rubber.

cohesive character and prevent cohesive union between the said rubber layer and a' subsequent of rubber, then further coating thethusly prepared rubber covered form with a second coating of rubber, the second coating of rubber having closely nested but non-adhering relationnested but entirely separate and independent. I

shi with the first throughout their contiguous surfaces to provide two convoluted bags in interrelationship and stripping said convoluted bags from said form.

2. The method of making a rubber article of the character described by depositing rubber upon a form which comprises producing an initial deposit of rubber having a cohesive treating at least a part ofthe exposed surface area of the initial deposit to destroyits cohesive character and prevent cohesive union between the said deposit and a subsequent deposit produced thereover, the treated area extendingat least around a circumference of the said deposit, pro- 1 ducing a second deposit of rubber over the first deposit, the second deposit being confined to the treated areas oi the first deposit and not extending to any untreated area of the first deposit.

and so contributes while it is in a cohesive condition, to destroy-its exposed surface,

a which comprises depositing rubber from a liquid said deposit whereby the two deposits, are closely inter-nested but'entirelyindepend ping both said deposits from said iorm.

3. The method 0! making a rubber product dispersion of rubber upon a form to produce an initial deposit or rubber having a cohesive exposed surface, treating the entire exposed area of the initial deposit to destroy its cohesive character and prevent cohesive union between the and a subsequent deposit produced thereover, producing a second deposit of rubber directly upon the treated area of the first deposit, the second deposit being at least as-extensive as the first deposit, wherebytwo rubber deposits of substantially the same shape and size are produced in inter-nested but mutually non-adherent relation throughout their contiguous surfaces, and stripping both said deposits from said form.

4. The method which comprises bag-like deposit or rubber having a cohesive outer surface, treating the-entire outer surface or the said deposit to destroy its cohesive character Patent No. 2,375,529. I

It is hereby certified that error as rasao tofeachothenandstripsuriace, treating the entire outer surface of the producing a csn'rrrrcms 0F cosssc'rr on.

posit produced thereoven producing a second over the treated surface or the first deposit to produce two inter-nested but non-adherent bag-like deposits, and closing the open end of the resulting doublewalled bag structure to provide a double-walled inflatable envelope.

5. The method which comprises producing a bag-like deposit of rubber having a cohesive outer said deposit to destroy its cohesive character and prevent cohesive union with a subsequent deposit produced thereover, producing a second bag-like deposit of rubber directly over the treated surface of the first deposit to produce two inter-nested but non-adherent bag-like deposits, closing the open end 01' the resulting doublewalled bagstructure to provide a double-walled inflatable enveloperand providing means for indating the envelope.

2 CARL L BEAL.

pr 10, 19b5- GARLJLQVBEAL.

appears in the printed specification I of the above numbered patent requiring correction as-follows: Page 1, second column, 1iru'e 22-25, for "cagulant""read coagulantfor "coagulent" read coagulant-; line 9, strike out column, line. 2, the words "-or cellulose ether"; and

page 2 first that the said Letters Patent should be read with this correction therein-that thesmne may conform to the cord of'i'he case in the, Patent Office.

- Signed and sealed' this 21st day of August, A, D. 19MB,

Seal) 7 Les-lie Frazer First Assistant Commissionerof Patents.

a which comprises depositing rubber from a liquid said deposit whereby the two deposits, are closely inter-nested but'entirelyindepend ping both said deposits from said iorm.

3. The method 0! making a rubber product dispersion of rubber upon a form to produce an initial deposit or rubber having a cohesive exposed surface, treating the entire exposed area of the initial deposit to destroy its cohesive character and prevent cohesive union between the and a subsequent deposit produced thereover, producing a second deposit of rubber directly upon the treated area of the first deposit, the second deposit being at least as-extensive as the first deposit, wherebytwo rubber deposits of substantially the same shape and size are produced in inter-nested but mutually non-adherent relation throughout their contiguous surfaces, and stripping both said deposits from said form.

4. The method which comprises bag-like deposit or rubber having a cohesive outer surface, treating the-entire outer surface or the said deposit to destroy its cohesive character Patent No. 2,375,529. I

It is hereby certified that error as rasao tofeachothenandstripsuriace, treating the entire outer surface of the producing a csn'rrrrcms 0F cosssc'rr on.

posit produced thereoven producing a second over the treated surface or the first deposit to produce two inter-nested but non-adherent bag-like deposits, and closing the open end of the resulting doublewalled bag structure to provide a double-walled inflatable envelope.

5. The method which comprises producing a bag-like deposit of rubber having a cohesive outer said deposit to destroy its cohesive character and prevent cohesive union with a subsequent deposit produced thereover, producing a second bag-like deposit of rubber directly over the treated surface of the first deposit to produce two inter-nested but non-adherent bag-like deposits, closing the open end 01' the resulting doublewalled bagstructure to provide a double-walled inflatable enveloperand providing means for indating the envelope.

2 CARL L BEAL.

pr 10, 19b5- GARLJLQVBEAL.

appears in the printed specification I of the above numbered patent requiring correction as-follows: Page 1, second column, 1iru'e 22-25, for "cagulant""read coagulantfor "coagulent" read coagulant-; line 9, strike out column, line. 2, the words "-or cellulose ether"; and

page 2 first that the said Letters Patent should be read with this correction therein-that thesmne may conform to the cord of'i'he case in the, Patent Office.

- Signed and sealed' this 21st day of August, A, D. 19MB,

Seal) 7 Les-lie Frazer First Assistant Commissionerof Patents. 

